Dear Black,
I must tell you that I don't know of a formula to work out this but there must be one, or else our whiz wheels wouldn't work. However, Drift, Heading, Track are al the same principles as the "boat" scenario we saw in our PPL nav books.
These things are quite simple to work out, you can either use the triangle of velocities method described in your book, or the basis that that derives from, which is force resolution which is physics. This is simply using trigonometry to resolve a set of forces into one vector quantity. You may be familiar with this if you a-level physics, but I don't know. Now my point is, I have a thing called "Modelus" which is a mathematical modelling program, and I have seen the "Boat" scenario on it, seeing as its all worked out by differentiation and simple equations, im sure there is a way to find the formula for these equations.
Sorry to drag the thread on with nothing concrete, but I will have a play tonight and see what I can do.
Rusty
[This message has been edited by Rusty Cessna (edited 21 February 2001).]